It is known to arrange an exhaust purification catalyst in an engine exhaust passage of an internal combustion engine and remove carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and other components which are contained in the exhaust gas. The exhaust purification catalyst has an activation temperature at which it can remove these components of the exhaust gas with a high efficiency. Right after starting an internal combustion engine which has been shut down for a long period of time, the exhaust purification catalyst becomes less than the activation temperature. It is therefore preferable to raise the temperature of exhaust purification catalyst to the activation temperature or more early in time.
Japanese Patent Publication No. 11-324765A discloses a direct injection spark ignition internal combustion engine which warms up an exhaust purification catalyst from start-up of the internal combustion engine until the exhaust purification catalyst becomes activated. In this direct injection spark ignition internal combustion engine, when controlling an air-fuel ratio of an air-fuel mixture to a stoichiometric ratio for combustion, fuel is injected in a suction stroke to thereby form a homogeneous air-fuel mixture which is comparatively leaner than the stoichiometric air-fuel ratio in a combustion chamber as a whole. Further, fuel is injected in a compression stroke to form an air-fuel mixture layer which is comparatively richer than the stoichiometric air-fuel ratio around a spark plug. It is disclosed that this internal combustion engine is able to increase a ratio of CO contained in burnt gas and easily susceptible to an oxidation reaction and is able to lower an HC ratio. Further, it is disclosed to set the ignition timing at a retarded side.
Further, in the prior art, it is known to raise a temperature of an exhaust purification catalyst in a short time at the time of cold start-up etc. by arranging a secondary air feed device for feeding air to an engine exhaust passage at an upstream side of an exhaust purification catalyst (for example, Japanese Patent Publication No. 05-79323A). The secondary air feed device feeds secondary air to the engine exhaust passage to raise the oxygen concentration. The feed of secondary air causes the unburned carbon monoxide (CO) or hydrocarbons (HC) which are contained in the exhaust gas to oxidize and raise the temperature of the exhaust gas so as to promote warm-up of the exhaust purification catalyst.
Japanese Patent Publication No. 2003-056392A discloses an internal combustion engine which is provided with an injector which directly injects fuel into a combustion chamber and an air feeding means for feeding air inside an exhaust passage. It is disclosed that this internal combustion engine injects fuel in a compression stroke and makes a combustion air-fuel ratio a stoichiometric air-fuel ratio or an air-fuel ratio at the fuel rich side from the stoichiometric air-fuel ratio when using the air feeding means to feed air into the exhaust passage.
Japanese Patent Publication No. 2008-208765A discloses a spark ignition type internal combustion engine which is provided with a fuel injector which injects fuel into an engine intake passage wherein the internal combustion engine is provided with a catalyst which is arranged in an exhaust passage of the internal combustion engine, an over-advancing means for making the ignition timing overly advanced, and an oxygen feeding means for feeding oxygen to the exhaust upstream of the catalyst when the ignition timing is overly advanced. Japanese Patent Publication No. 2010-112289A discloses a control device of an internal combustion engine which is provided with a secondary air feed device wherein heat of a radiator etc. is introduced into the secondary air feed device to thaw out a frozen part of the secondary air feed device. Japanese Patent Publication No. 2011-111895A discloses a control device of an internal combustion engine which corrects an amount of discharge of a secondary air pump so that a temperature of the exhaust gas which flows into the catalyst becomes a suitable temperature.